1. Field of the Invention
The invention relates generally to an energy storing brake for a vehicle, such as an industrial truck, having a rotating brake rotor and a non-rotating braking body that can move relative to the brake rotor, which braking body can be pressed by an energy storing mechanism, such as a spring, against the brake rotor, and which can be detached from the brake rotor by a brake lifter against the force of the energy storing mechanism.
2. Description of the Prior Art
Energy storing brakes of the above type are used in vehicles of various types, including industrial trucks, as parking brakes. These parking brakes are always released during normal operation of the vehicle. In this released state, the brake lifter creates an air gap between the brake rotor and the braking body. When the vehicle is turned off or when a switch for the parking brake is actuated, the brake lifter is deactivated, whereupon the energy storing brake engages as a result of the force of the energy storing mechanism. The braking force of this conventional energy storing brake is fixed and cannot be varied during the operation of the vehicle.
The prior art also includes energy storing brakes having an electromagnet as the brake lifter. The braking torque can be controlled by an operator during operation of the vehicle. For this purpose, DE 195 48 517 A1, for example, teaches that it is possible to alter the current flowing through the electromagnet to adjust the braking torque. However, the electrical control device required for this purpose is very complex and expensive. An energy storing brake of this type also has the disadvantage that the maximum braking torque is determined by the force of a spring, and during a braking process, the maximum braking force cannot be increased beyond the value defined by the spring.
Therefore, it is an object of the invention to provide a brake that can be continuously actuated by means of a simple device and in which the maximum braking force can be influenced or controlled by the operator during the braking of the vehicle.